JP2018519778A - Rotating electric machine, especially electric motor, with rotor limiting flux loss - Google Patents

Abstract

The present invention is formed by a rotor body having a plurality of stacked plates (16) and installed on a rotor shaft (14), the plurality of plates being an outer edge portion (36) and an inner edge portion (38) of the plurality of plates. The present invention relates to an electric machine including a rotor (10) including a housing (40) for accommodating a magnetic flux generation unit (20) and a magnetic pole expansion unit (42) positioned between the stator (12).
According to the present invention, the magnetic pole expansion part (42) is connected to the inner edge part (38) of the plurality of plates by a connection bridge (48).
[Selection] Figure 3

Description

  The present invention relates to a rotating electric machine, in particular an electric motor, comprising a rotor housed in a stator.

In general, the rotor is formed from a rotor body that holds a magnetic flux generation section such as a permanent magnet, and is supported by a rotor shaft.
This rotor generally holds an electrical winding (or armature winding) that can generate a magnetic field, and in the stator that allows the rotor to be driven in rotation relative to the magnetic field generated by the magnet. Is housed in.

It is known that the magnets are uniformly distributed in the circumferential direction, extend along the entire axial length of the rotor body, and are arranged in a radially closed housing.
These housings thus define a radial pole expansion between them that allows the path of magnetic flux coming from the magnet.

  This arrangement is satisfactory, but nevertheless has minor drawbacks.

Specifically, the magnetic flux is not completely guided by the magnetic pole expansion portion, and there is still a loss at the outer peripheral portion of the rotor, particularly at the outer ends of these extensions.
In addition, magnetic flux loss still exists at the connection between the magnetic pole expansion portion and the rotor shaft.

Because of these various losses, the electrical machine cannot achieve the required performance.
Therefore, it is necessary to change the size of the rotor and / or increase the amount of magnetic flux generated from the magnet in order to achieve the required performance.

  The present invention proposes to overcome the above-mentioned drawbacks by using an electric machine with minimal magnetic flux loss in the rotor.

  For this purpose, the present invention is formed by a rotor body having a laminated body composed of a plurality of plates and installed on a rotor shaft, and the plurality of plates are disposed between outer edges and inner edges of the plurality of plates. An electric machine comprising a rotor having a housing for accommodating a magnetic flux generating part and a magnetic pole expansion part located at a position, and a stator, wherein the magnetic pole expansion part is connected to the inner edge part of the plurality of plates by a connection bridge The present invention relates to an electrical machine that is connected.

  The plurality of plates may include a connection surface that connects the bridge and the inner edge.

  The bridge may have a circumferential dimension smaller than a circumferential dimension of the magnetic pole expansion portion.

  The bridge may have a circumferential dimension corresponding to approximately 10% of a circumferential dimension of the magnetic pole expansion portion.

  The bridge may have a height dimension corresponding to approximately 10% of a height measured between an outer edge and an inner edge of the plurality of plates.

  The plurality of plates may have an air space between two successive magnetic pole expansion portions and face the housing.

1 is a perspective view of a rotor and a stator of an electric machine according to the present invention. FIG. 2 is a schematic view of elements of the rotor of FIG. 1. FIG. 3 is an enlarged view of details of a rotor by a circle A in FIG. 2.

  Other features and advantages of the present invention will become apparent upon reading the following description, given solely by way of non-limiting illustration and attached.

  As shown in FIG. 1, a rotating electrical machine, in this case an electric motor, when assembled, is concentrically nested one inside the other to allow the rotor 10 and stator to rotate freely. 12.

The rotor is provided with a shaft 14 on which a laminate composed of a plurality of flat and ferromagnetic plates 16, which is known per se, is installed, and these plates 16 form a rotor body 18. Are assembled by known means.
The rotor holds a plurality of magnetic flux generators, in this case, a plurality of permanent magnets 20, which are in the shape of a rod having a length substantially equal to the length of a laminate composed of a plurality of plates in the illustrated example.

Further, the stator includes a laminated body composed of a plurality of flat plates 22 having the same ferromagnetism, and these plates 22 are like threaded through bolts 24 so as to form a cylindrical stator body 26. They are joined by any known means.
The annular peripheral portion of the stator body has a plurality of radially extending slots that are open toward the center of the stator and extend along the entire circumference of the annular stator. I have. These slots are designed to accommodate armature windings 30 that are secured by known means.

  Here, reference is further made to FIGS. 2 and 3 showing the structure of the rotor plate 16.

The plate has a substantially annular configuration having a central hole 32 that houses the rotor shaft and an annular flat peripheral surface 34 having an outer peripheral edge 36 and an inner peripheral edge 38.
The annular flat surface holds a series of housings 40 that are substantially rectangular along the radial direction, and the housings 40 are evenly distributed circumferentially over this surface to accommodate permanent magnets. Yes. Thus, these housings define a radial pole expansion portion 42 therebetween.
The housing has a lower edge 44 that is spaced apart from the inner edge 38 of the flat circumferential surface and an upper edge 46 that is spaced somewhat from the outer edge 36 of the flat circumferential surface.

The magnetic pole expansion portion is approximately 12% of the height D of the flat surface 34 measured between the circumferential dimension Dpc smaller than the minimum circumferential dimension Dep of the magnetic pole expansion portion and the edges 36 and 38. A connection bridge 48 having a corresponding radial height Hp is connected to a connection surface 47 connecting the inner edge 38 and the bottom 44.
Preferably, the circumferential dimension Dpc is about 10% of the circumferential dimension Dep.

More specifically, referring to FIG. 3, the bridge 38 includes a radially extending strip 50 having a curved connecting portion 52 that connects the strip to the inner edge 44 of the housing. The strip 50 is continuous with the inner edge 44.
Advantageously, the bridge comprises two convex surfaces 54, which allow the bridge to be connected to each end 56 along the radial direction of the pole expansion, thereby the orientation of the housing The tip 58 is formed on the surface.

  As can be seen, this bridge makes it possible to form an inverted T-shaped housing, where the horizontal bar in the inverted T-shaped housing has an inner edge 44 and a convex surface 54 of two adjacent pole expansion parts. And the vertical bars in the inverted T-shaped housing are delimited by the radial ends 56 of these pole expansions and the outer edge 46 of the housing.

  As best shown in FIG. 3, the circumferential dimension Dpc is considered in the strip 50, the circumferential dimension Dep is considered between the tips of the tips 58, and the height Hp is the top of the convex surface 54. It is considered between the inner edge 44 of the housing 40.

The section included between the outer peripheral edge 36 and the outer edge 46 of the housing is advantageous in that it includes the space 60 referred to as the airspace described above.
In order to obtain a rotor body of a desired length by aligning the housing and the magnetic pole expansion part with each other, once a plurality of plates are stacked and joined, the permanent magnet is thus inserted into the cavity formed by the housing. And is secured by any known means.

  The rotor shaft is then attached to the rotor body and the assembly is then housed in a stator to produce an electrical machine having the necessary components such as commutators, connectors and the like.

When the electric machine is in operation, thanks to the small circumferential dimensions and low height of the bridge 48, this bridge quickly saturates the magnetic flux and thus limits the flux loss.
In addition, the airspace 60 between the magnetic pole expansion portions blocks the transmission of magnetic flux between two adjacent magnetic pole expansion portions, which can limit only the magnetic flux loss.

  Of course, it is within the ability of those skilled in the art to design bridges taking into account various constraints such as the centrifugal force of the rotor, the magnetic force from the magnet, and the magnetic attractive force between the rotor and the stator.

Claims (6)

Formed by a rotor body (18) having a laminate composed of a plurality of plates (16) and installed on a rotor shaft (14), the plurality of plates are connected to an outer edge (36) and an inner edge ( 38), an electric machine including a rotor (10) including a housing (40) for accommodating a magnetic flux generation section (20) and a magnetic pole expansion section (42) positioned between the stator and a stator (12). And
The magnetic pole expansion part (42) is connected to the inner edge part (38) of the plurality of plates by a connection bridge (48),
Electric machine. The plurality of plates include a connection surface (47) for connecting the bridge (48) and the inner edge (38),
The electric machine according to claim 1. The bridge has a circumferential dimension (Dpc) smaller than a circumferential dimension (Dep) of the magnetic pole expansion part,
The electric machine according to claim 1 or 2. The bridge has a circumferential dimension (Dpc) corresponding to approximately 10% of a circumferential dimension (Dep) of the magnetic pole expansion part,
The electric machine according to claim 1. The bridge has a height dimension (Hp) corresponding to approximately 10% of a height measured between an outer edge (36) and an inner edge (38) of the plurality of plates. To
The electric machine according to claim 1. The plurality of plates are provided with an air space (60) between two continuous magnetic pole expansion portions, and face the housing (40).
The electric machine according to claim 1.

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